Vertical-cavity, surface-emitting lasers of the sort disclosed by Jewell et al. in U.S. Pat. No. 4,949,350 offer many advantages for use in optical processing. Two-dimensional, addressable arrays of these lasers can be inexpensively fabricated on a single substrate and can provide many parallel channels. To data, such arrays have been addressed only electrically. Matrix-type electrical addressing allows large arrays to be addressed but is incompatible with the independent and simultaneous addressing needed for general optical processing. Independent and simultaneous electrical addressing requires an electrical connection for each of the lasers, thus limiting the size of the array.
Optically controlled light sources have been implemented for edge-emitting lasers and light-emitting diodes (LEDs), as has been disclosed by Katz et al. in "A monolithic integration of GaAs/GaAlAs bipolar transistor and heterostructure laser," Applied Physics Letters, volume 37, 1980, pp. 211-213 and by Bar-Chaim et al., in "Monolithic integration of a GaAlAs buried-heterostructure laser and a bipolar phototransistor,"ibid., volume 40, 1982, pp. 556-557. However, the one-dimensional geometry of these devices makes it very difficult to adapt this approach to two-dimensional arrays exhibiting optical gain.